Abstract In this paper the application of homotopy equivalence transformation (HET) of topological space sets to the topological classification of states and defects in ordered media is discussed. Firstly, an argument is pres-ented about the idea that for simplifying and even working out the classification and constructing homotopy class sets into groups, it is crucial to utilize the HET. As the theoretical basis for doing this we sum up the relevant results in homotopy theory into a theorem, called the "invariance theorem for HET". Secondly, in order to favor the utilization of this theorem, several propositions on homotopy equivalence between space sets are given. Finally, the absolute and relative topological dassification of states and defects is systemtically studied. The main results obtained are embodied in eight theorems.
Received: 06 August 1992
Accepted manuscript online:
Fund: Project supported by the National Natural Science Foundation of China.
Cite this article:
LI BO-ZANG (李伯臧), YAN FENG-LI (阎凤利) APPLYING THE HOMOTOPY EQUIVALENCE TRANSFORMATION OF TOPOLOGICAL SPACE SETS TO THE TOPOLOGICAL CLASSIFICATION OF STATES AND DEFECTS IN ORDERED MEDIA 1993 Acta Physica Sinica (Overseas Edition) 2 321
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